Pronation is the term used to describe a natural movement of the foot when walking. When the gait is normal, the heel strikes the ground first. As weight is transferred forward, the arch of the foot flattens and the foot rolls slightly inwards. Body weight is then placed on the ball of the foot and toes, and the foot straightens and turns outwards as the toes push off. Overpronation occurs when the foot rolls inward too far. This causes all the muscles and tendons of the lower leg to twist excessively. Regular overpronation is believed to contribute to the development of many knee, lower leg and foot injuries such as heel spurs, plantar fasciitis, tendinitis and bunions. It is thought that as much as 60% of the population may overpronate.
Pronation can occur as an overuse syndrome in active runners, where a great deal of stress is placed on ligaments and tendons that support the medial column. Obesity is another predictor for pronation and deterioration of the medial ligaments and posterior tibial tendon due to excessive stress on these tissues. Acute Trauma can also lead to over-pronation when ligaments are torn or tendon is ruptured. Once again this can lead to a collapse of the medial column. Arthritic conditions involving the knee joint when the joint is in varus (inner collapse) posture, this places the center of gravity over the ankle joint rather than the foot causing undue pressure on the inner ankle.
Overpronation may have secondary effects on the lower legs, such as increased rotation of the tibia, which may result in lower leg or knee problems. Overpronation is usually associated with many overuse injuries in running including medial tibial stress syndrome, or shin splints, and knee pain Individuals with injuries typically have pronation movement that is about two to four degrees greater than that of those with no injuries. Between 40% and 50% of runners who overpronate do not have overuse injuries. This suggests that although pronation may have an effect on certain injuries, it is not the only factor influencing their development.
The best way to discover whether you have a normal gait, or if you overpronate, is to visit a specialty run shop, an exercise physiologist, a podiatrist or a physical therapist who specializes in working with athletes. A professional can analyze your gait, by watching you either walk or run, preferably on a treadmill. Some facilities can videotape your gait, then analyze the movement of your feet in slow-motion. Another (and less costly) way is to look at the bottom of an older pair of run shoes. Check the wear pattern. A person with a normal gait will generally see wear evenly across the heel and front of the shoe. A person who overpronates will likely see more wear on the OUTside of the heel and more wear on the INside of the forefoot (at the ball). A person who supinates will see wear all along the outer edges of the shoe. You can also learn about your gait by looking at your arches. Look at the shape your wet feet leave on a piece of paper or a flat walking surface.
Non Surgical Treatment
Over-Pronation can be treated conservatively (non-surgical treatments) with over-the-counter orthotics. These orthotics should be designed with appropriate arch support and medial rearfoot posting to prevent the over-pronation. Footwear should also be examined to ensure there is a proper fit. Footwear with a firm heel counter is often recommended for extra support and stability. Improper fitting footwear can lead to additional problems of the foot.
Pronation forces us to bear most of our weight on the inner border of our feet. Custom-made orthotics gently redistributes the weight so that the entire foot bears its normal share of weight with each step we take. The foot will not twist out at the ankle, but will strike the ground normally when the orthotics is used. This action of the custom-made orthotics will help to prevent shin splints, ankle sprains, knee and hip pain, lower back pain, nerve entrapments, tendonitis, muscle aches, bunions, generalized fatigue, hammer toes, and calluses.